<!DOCTYPE html>
<html>

	<head>
		<meta charset="UTF-8">
		<title>使用对象控制画布上的元素</title>
		<style>
			#canvas {
				background: #ddd;
				margin: 0 auto;
				display: block;
			}
		</style>
	</head>

	<body>
		
		<canvas id="canvas" width="500px" height="500px"></canvas>
        
        <script src="js/1.js"></script>
	</body>

</html>